At certain zoom levels, labels are duplicated across features when they should not be.
With two features called "MQ" and "N2", up to zoom 12, the label "MQ" is duplicated across both features. At zoom 13 and closer, they display correctly.
CodePen: https://codepen.io/emeraldimp/pen/jEOExYr - Notice that the two features are both labeled "MQ". Zoom in once and notice that the one to the SE becomes N2.
It seems to be related specifically to the names MQ and N2. If I change either, they appear correctly. Here is the same example but with "WQ" instead of "MQ": https://codepen.io/emeraldimp/pen/ByayVBK
It may be related to version 4.31 - when using codepen, it happens no matter which version I use, but in the project it occurs using 4.31 (and 4.32) but not with 4.29 or 4.30.